Death of photoreceptor cells is a consequence of many acute as well as chronic retinal diseases which lead to severe vision loss in patients. If photoreceptors could be helped to survive the period of disease, the visual outcomes for patients would be significantly better. Retinal degenerative disease and injury are among the leading causes of irreversible vision loss and blindness in the United States and the developed world, affecting hundreds of thousands of people every year and resulting in billions of dollars in added healthcare costs and lost productivity. A problem limiting the efficacy of current treatments is that currently there are no interventions that can specifically prevent photoreceptor cell death; therefore, a safe, potent, photoreceptor protectant would provide a significant visual benefit to hundreds of thousands of people every year. ONL Therapeutics is developing a product candidate, a novel small peptide inhibitor of the FAS- receptor (ONL-101), for peri-operative adjunctive use in patients with acute retinal detachment (an orphan indication), with the goal of preventing photoreceptor cell death until definitive surgical repair can occur. This acute indication provides a rapid development pathway that will lay the groundwork for future expansion of ONL-101 development for chronic indications such as age-related macular degeneration. The product for acute retinal detachment will be a prescription drug for single dose intravitreal injection (an established route of administration in ophthalmology). Upon completion of this SBIR Phase II study, ONL Therapeutics will have tested and validated the hypothesis that a safe and effective formulation for intravitreal injection of ONL-101 can be developed for use in human clinical trials. We will demonstrate that: 1) Intravitreal injection of ONL-101 is safe, and results in no significant ocular or systemic toxicity, 2) Pharmaceutical grade ONL-101 for use in clinical trials can be produced, and 3) A Phase 1/2 clinical trial can be designed to test the safety and efficacy of ONL-101 in humans. The work presented in this Phase II is the next step required for the commercialization of ONL-101, and the results obtained will allow for finalization of the IND package required to begin clinical trials for the ue of ONL-101 as an adjunctive treatment in patients with retinal detachments.